heads for 340

When I did my J-heads for my race car 2.02/1.60... Go with a chevy speck valve +.100 over, same length as a stock Chrysler valve with the bronze guild... Parts are cheaper, smaller stem, 11/32 vs 3/8 = more flow, less weight, chevy speck locks and retainers and the springs are the same dia... Since these are aftermarket parts they arent really brand specific, just less money... Going to do the same thing to a set of 308 heads for a 340 build I am going to do...